map()

template<concepts::product_type Tuple, typename Function, concepts::sized_product_type< size_v< Tuple > >... Tuples>
requires (concepts::compatible_product_types<Tuple, Tuples...> && _::supports_call<Function, Tuple &&, Tuples && ...>)

auto kumi::map ( Function f, Tuple && t0, Tuples &&... others )

inlinenodiscardconstexpr

Apply the Callable object f on each tuples' elements.

Applies the given function to all the tuples passed as arguments and stores the result in another tuple, keeping the original elements order.

Note

Does not participate in overload resolution if tuples' size are not equal or if f can't be called on each tuple's elements.

Parameters

f	Callable function to apply
t0	Tuple to operate on
others	Tuples to operate on

Returns

The tuple of f calls results.

Helper type

namespace kumi::result
{
  template<typename Function, product_type T, product_type... Ts> struct map;
 
  template<typename Function, product_type T, product_type... Ts>
  using map_t = typename map<Function,Tuple>::type;
}

Computes the return type of a call to kumi::map

Examples:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  auto lhs = kumi::tuple{1,2,3};
  auto rhs = kumi::tuple{2.5,3.6,4.7};
 
  auto res = kumi::map( [](auto l, auto r) { return l*r; }, lhs, rhs);
 
  std::cout << res << "\n";
}

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
  auto lhs = kumi::record{"a"_id = 1,"b"_id = 2,"c"_id = 3};
  auto rhs = kumi::record{"a"_id = 2.5,"b"_id = 3.6,"c"_id = 4.7};
 
  auto res = kumi::map( [](auto l, auto r) { return l*r; }, lhs, rhs);
 
  std::cout << res << "\n";
}